Use positional only format.

aiogram/bot/api.py

@@ -47,7 +47,8 @@ async def _check_result(method_name, response):
     """
     if response.status != 200:
         body = await response.text()
-        raise TelegramAPIError(f"The server returned HTTP {response.status}. Response body:\n[{body}]",
+        raise TelegramAPIError("The server returned HTTP {0}. Response body:\n[{1}]".format(
+            response.status, body),
                                method_name, response.status, body)
 
     result_json = await response.json(loads=json.loads)
@@ -56,9 +57,9 @@ async def _check_result(method_name, response):
         body = await response.text()
         code = result_json.get('error_code')
         description = result_json.get('description')
-        raise TelegramAPIError(f"Error code: {code} Description {description}",
+        raise TelegramAPIError("Error code: {0} Description {1}".format(code, description),
                                method_name, response.status, body)
-    log.debug(f"Response for '{method_name}': {result_json}")
+    log.debug("Response for '{0}': {1}".format(method_name, result_json))
     return result_json.get('result')
 
 
@@ -120,7 +121,8 @@ async def request(session, token, method, data=None, files=None) -> bool or dict
     :param files: files
     :return: bool or dict
     """
-    log.debug(f"Make request: '{method}' with data: {data or {}} and files {files or {}}")
+    log.debug("Make request: '{0}' with data: {1} and files {2}".format(
+        method, data or {}, files or {}))
     data = _compose_data(data, files)
     url = Methods.api_url(token=token, method=method)
     async with session.post(url, data=data) as response:

aiogram/dispatcher/__init__.py

@@ -93,7 +93,7 @@ class Dispatcher:
                 continue
 
             if updates:
-                log.info(f"Received {len(updates)} updates.")
+                log.info("Received {0} updates.".format(len(updates)))
                 offset = updates[-1].update_id + 1
                 await self.process_updates(updates)
 

aiogram/dispatcher/handler.py

@@ -109,4 +109,4 @@ class NextStepHandler:
 
 
 def gen_identifier(chat_id, from_user_id):
-    return f"{chat_id}:{from_user_id}"
+    return "{0}:{1}".format(chat_id, from_user_id)

aiogram/dispatcher/state.py

@@ -501,7 +501,9 @@ class Controller:
         self.delete(key)
 
     def __str__(self):
-        return f"{self._chat}:{self._user} - {self._state}"
+        return "{0}:{1} - {2}".format(
+            self._chat, self._user, self._state
+        )
 
 
 class AsyncController:
@@ -611,7 +613,9 @@ class AsyncController:
         raise RuntimeError("Item assignment not allowed with async storage")
 
     def __str__(self):
-        return f"{self._chat}:{self._user} - {self._state}"
+        return "{0}:{1} - {2}".format(
+            self._chat, self._user, self._state
+        )
 
 
 class StateMachine:
@@ -650,7 +654,9 @@ class StateMachine:
         :param state: 
         :return: 
         """
-        log.debug(f"Set state for {chat}:{user} to '{state}'")
+        log.debug("Set state for {0}:{1} to '{2}'".format(
+            chat, user, state
+        ))
         self.storage.set_state(chat, user, state)
 
     def get_state(self, chat, user):
@@ -669,7 +675,7 @@ class StateMachine:
         :param user: 
         :return: 
         """
-        log.debug(f"Reset state for {chat}:{user}")
+        log.debug("Reset state for {0}:{1}".format(chat, user))
         self.storage.del_state(chat, user)
 
     async def process_message(self, message):
@@ -686,11 +692,15 @@ class StateMachine:
             raise SkipHandler()
 
         if state not in self.steps:
-            log.warning(f"Found unknown state '{state}' for {chat_id}:{from_user_id}. Condition will be reset.")
+            log.warning("Found unknown state '{0}' for {1}:{2}. Condition will be reset.".format(
+                state, chat_id, from_user_id
+            ))
             self.del_state(chat_id, from_user_id)
             raise SkipHandler()
 
-        log.debug(f"Process state for {chat_id}:{from_user_id} - '{state}'")
+        log.debug("Process state for {0}:{1} - '{2}'".format(
+            chat_id, from_user_id, state
+        ))
         callback = self.steps[state]
         controller = Controller(self, chat_id, from_user_id, state)
         await callback(message, controller)
@@ -731,7 +741,9 @@ class AsyncStateMachine:
         :param state: 
         :return: 
         """
-        log.debug(f"Set state for {chat}:{user} to '{state}'")
+        log.debug("Set state for {0}:{1} to '{2}'".format(
+            chat, user, state
+        ))
         await self.storage.set_state(chat, user, state)
 
     async def get_state(self, chat, user):
@@ -750,7 +762,7 @@ class AsyncStateMachine:
         :param user: 
         :return: 
         """
-        log.debug(f"Reset state for {chat}:{user}")
+        log.debug("Reset state for {0}:{1}".format(chat, user))
         await self.storage.del_state(chat, user)
 
     async def process_message(self, message):
@@ -767,11 +779,15 @@ class AsyncStateMachine:
             raise SkipHandler()
 
         if state not in self.steps:
-            log.warning(f"Found unknown state '{state}' for {chat_id}:{from_user_id}. Condition will be reset.")
+            log.warning("Found unknown state '{0}' for {1}:{2}. Condition will be reset.".format(
+                state, chat_id, from_user_id
+            ))
             await self.del_state(chat_id, from_user_id)
             raise SkipHandler()
 
-        log.debug(f"Process state for {chat_id}:{from_user_id} - '{state}'")
+        log.debug("Process state for {0}:{1} - '{2}'".format(
+            chat_id, from_user_id, state
+        ))
         callback = self.steps[state]
         controller = AsyncController(self, chat_id, from_user_id, state)
         await callback(message, controller)

aiogram/exceptions.py

@@ -8,7 +8,7 @@ class ValidationError(Exception):
 class TelegramAPIError(Exception):
     def __init__(self, message, method, status, body):
         super(TelegramAPIError, self).__init__(
-            f"A request to the Telegram API was unsuccessful.\n{message}")
+            "A request to the Telegram API was unsuccessful.\n" + message)
         self.method = method
         self.status = status
         self.body = body

aiogram/types/base.py

@@ -66,7 +66,7 @@ class Deserializable:
         Bot instance
         """
         if not hasattr(self, '_bot'):
-            raise AttributeError(f"{self.__class__.__name__} is not configured.")
+            raise AttributeError("{0} is not configured.".format(self.__class__.__name__))
         return getattr(self, '_bot')
 
     @bot.setter

aiogram/utils/markdown.py

@@ -64,11 +64,11 @@ def hpre(*content, sep='\n'):
 
 
 def link(title, url):
-    return f"[{_escape(title)}]({url})"
+    return "[{0}]({1})".format(_escape(title), url)
 
 
 def hlink(title, url):
-    return f"<a href=\"{url}\">{_escape(title)}</a>"
+    return "<a href=\"{0}\">{1}</a>".format(url, _escape(title))
 
 
 def escape_md(*content, sep=' '):